The invention relates to an axial-symmetric joint of high thermal load capacity, especially of a lens and a cylindrical lens mounting.
If a cylindrical body, which is mounted in a ring, expands less than the ring on heating because of different thermal expansion coefficients, an existing gap between ring and cylinder becomes larger with the increase in temperature.
If the gap between the ring and cylinder is filled with cured adhesive for fixing the cylinder, the adhesive is stretched with the change of gap thickness. Stretchings of this kind result in turn in stresses, which are transferred to the cylinder and to the ring. In the case of the cylinder this may be, for example, an optical lens or a shaft and in the case of the ring a lens mounting or a hub.
A mounting for optical lenses is known from German Patent 34 37 228 in which the materials of the four-part mounting are chosen with respect to their respective thermal expansion coefficients in such a manner that a stretching compensation results acting only in the axial direction of the lens. Radial extension differences are compensated in this known mounting by a permanently elastic casting compound and an elastically deformed "O" ring. Depending on the stiffness of these intermediate elements, stresses are caused by the elastic radial stretchings, which prevent an application of this mounting technology, especially for high-quality low-stress or stress-free microoptics for polarization equipment.
It is therefore the object of the present invention to provide a joint in which neither structurally induced internal stresses nor temperature stresses caused by internal or external effects are transmitted to the central cylindrical mounting part in a radial direction (lens).